Formation of Free Radicals in Human Skin during Irradiation with Infrared Light  Maxim E. Darvin, Stefan F. Haag, Jürgen Lademann, Leonhard Zastrow, Wolfram Sterry, Martina C. Meinke  Journal of Investigative Dermatology  Volume 130, Issue 2, Pages 629-631 (February 2010) DOI: 10.1038/jid.2009.283 Copyright © 2010 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Box plot of the cutaneous concentration of β-carotene (left) and lycopene (right) before and after IR irradiation, in all volunteers, with SDs. Diamonds—initial level before irradiation; stars—after IR irradiation. Journal of Investigative Dermatology 2010 130, 629-631DOI: (10.1038/jid.2009.283) Copyright © 2010 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Average decay of 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCA) in porcine skin biopsies (six samples) in the absence of (1) and during (2) IR irradiation. IR irradiation was performed on the porcine skin surface for 30minutes with a power density of 115mWcm−2. Journal of Investigative Dermatology 2010 130, 629-631DOI: (10.1038/jid.2009.283) Copyright © 2010 The Society for Investigative Dermatology, Inc Terms and Conditions